December 8, 2018
Summary: The ground fog last night has lifted into a low overcast and has expanded to cover the entire San Joaquin Valley and most of the Sacramento Valley and adjacent foothills. The base of the overcast is quite uniform, ranging from 900 feet at Visalia to 1,100 feet at Fresno. Temperatures are also very uniform this morning and are huddled in the upper 40s. satellite imagery shows a considerable amount of high clouds moving in from the west/southwest. This will weaken the amount of sunshine reaching the ground, thus most locations will likely not see any sunshine this afternoon. I wouldn’t be surprised if temperatures at most locations ended up in the lower 50s this afternoon. Locations that win the grand prize and see a bit of sun will jump into the mid to upper 50s.
Two disturbances will affect central California over the next 72 hours. The first will be a weak trough moving through late Monday into early Tuesday. It still appears any measurable rain will be confined north of a Monterey/Merced line with the exception of the Sierra Nevada. System number two is what we call an inside slider. It will move rapidly through the Pacific Northwest and into the Great Basin on Wednesday. This will briefly turn the winds aloft to a north/northwest direction, injecting marginally cooler air into the region. It will be interesting to see whether these two systems are strong enough to rid the valley of its fog and low overcast.
By Wednesday night and Thursday, upper level high pressure will again build in from the west. The storm track will ride over the top of the high and into the Pacific Northwest, clipping northern California from time to time. Longer term, it looks like the next chance of rain will be about a week from Monday. Models seem to be trending towards a big low off the coast of the Pacific Northwest with a moist, westerly flow moving into California. This could result in additional Pacific storms later next week.
Forecast: Low overcast today through Monday morning. Variable cloudiness Monday afternoon through Tuesday with possible extensive fog and low clouds. Partly cloudy Wednesday with areas of night and morning fog. Fog and/or low clouds Thursday through Sunday with partial afternoon clearing.
Short Term:
Madera 53/47/55/43/55 | Reedley 53/47/55/43/55 | Dinuba 52/46/55/43/56 | |
Porterville 54/46/55/43/56 | Lindsay 54/46/55/42/56 | Delano 53/47/54/44/55 | |
Bakersfield 57/45/56/45/56 | Taft 59/49/56/47/56 | Arvin 59/48/59/44/54 | |
Lamont 56/48/55/44/55 | Pixley 54/48/55/44/56 | Tulare 52/47/54/41/54 | |
Woodlake 53/47/55/43/55 | Hanford 54/47/55/43/55 | Orosi 54/46/55/42/55 |
Seven Day Forecast:
Wednesday
AM fog/partly cloudy 37/56 |
Thursday
AM fog/PM sun 40/57 |
Friday
AM fog/PM sun 42/55 |
Saturday
AM fog/PM sun 45/54 |
Sunday
Increasing cloudiness 43/58 |
Two Week Outlook: December 16 through December 22: This model is back to giving central California a better than even chance of rain during this period. It does show at least one Pacific storm moving through with possibly more. The main flow will be out of the west to northwest, so temperatures should run a bit above average, unless the fog takes over.
December: It’s been quite some time since this model has actually projected above average precipitation, but the good news is that is the case. It appears the dominant pattern for the month will maintain winds generally out of the west or northwest, which would favor above average temperatures.
December, January, February: It’s been a long time since the 90 day outlook projected above average precipitation for December through February, in other words the winter months. It also continues the better than even chance that over the next three months, temperatures will largely be above average. However, like any winter there will be below average periods as well.
Winds: Winds will be generally at or less than 6 MPH with extended periods of near calm conditions through Wednesday.
Rain: A weak trough of low pressure will move through early Tuesday. It still appears the southern extent of precipitation will reach as far south as a Monterey/Merced line, however the remainder of the valley will more than likely remain dry. After Tuesday, the next chance of precipitation will be late Sunday and early Monday of next week. Hopefully this pattern shapes up the way it’s appearing on paper as a big low sets up shop off the coast of the Pacific Northwest with a moist westerly flow into California. This pattern could introduce further chance of rain later next week.
Frost Discussion: All locations will be above 32 degrees tonight through Tuesday morning. Wednesday and Thursday mornings will see possible low to mid 30s, but only if the valley is scoured of its low level moisture, meaning fog and low clouds. A weather system will dive into the Great Basin Wednesday with a brief north/northwest flow. The problem is, low level winds may not be enough to truly break the inversion. If the fog and low clouds hang in there, above freezing conditions will prevail. Nothing on medium range models indicating a particularly cold pattern coming up.
Afternoon Dew Points Today: Mid to upper 40s. Kern: Mid to upper 40s.
Humidity: Porterville: 75%/95%, Bakersfield: 70%/90%
Actual Humidity December 8, 2018: Delano, NA, Porterville, 99%/87%
Percentage of Sunshine Today/Tomorrow: Visalia: Today: 0% tomorrow 20% Bakersfield: Today: 20% Tomorrow: 30%
ET Rates Over the Past Seven Days: Stratford .19, Parlier .22, Blackwell .28, Lindcove .20, Arvin .NA, Orange Cove .29, Porterville .20, Delano NA Courtesy University of California *=estimate, NA=not available.
Seven Day Soil Temperatures: Stratford 57, Parlier 54, Blackwell 56, Lindcove, 59, Arvin, 56, Orange Cove 54, Porterville 54, Delano 52
Record Temperatures: 70/23. Average Temperatures: 56/35
Heating Degree Days this Season: 443 -207
Courtesy of the NWS
Average temperature for December so far: 49.8 +3.9
Precipitation: Seasonal total/average/above or below average:
Since Oct 1, 2018 Fresno: 1.92 season. or -.14, Month to Date: .15 -.21
Since Oct 1, 2018, Bakersfield: 1.20, or +.04. Month to Date: .52 +.30
Water year season is from October 1st through September.
Chilling Hours November 1st through February 28: Orange Cove, 202, Parlier, 233 , Arvin, 179 Shafter, 245 Stratford, 207, Delano 214, Lindcove, 261, Porterville, 401
. Hours at 45 or below 45.
Sunrise: 7:01 am Sunset: 4:43 pm. Hours of Daylight: 9:43
Yesterday’s Weather:
MAE : Madera 253 : DH1600 / 59 / 41 / 0.00 /
FAT : Fresno Airport 333 : DH1600 / 58 / 44 / 0.00 /
HJO : Hanford Airport 242 : DH1600 / 57 / 44 / 0.00 /
NLC : Lemoore Naval AS 234 : DH1600 / 55 / 42 / 0.00 /
BFL : Bakersfield Airport 496 : DH1600 / 54 / 42 / 0.00 /
VIS : Visalia Airport 292 : DH1600 / 55 / 43 / 0.00 /
ATEC1 : Avenal 787 : DH1554 / 59 / 42 / 0.00 /
PTV : Porterville Airport 442 : DH1600 / 54 / 38 / 0.00 /
TFTC1 : Taft 759 : DH1556 / 55 / 40 / 0.00 /
Rainfall: Water year Oct 1st through September 30th
24hr Season % L.Y. % Ave. Ave. yearly total
STOCKTON 0.00 3.87 129 0.91 30 3.01 14.06
MODESTO 0.00 3.05 123 0.98 40 2.48 13.11
MERCED 0.00 2.69 120 1.03 46 2.24 12.50
MADERA 0.00 2.42 104 0.32 14 2.32 12.02
FRESNO 0.00 1.92 93 0.37 18 2.06 11.50
HANFORD 0.00 1.71 101 0.37 22 1.69 10.10
BAKERSFIELD 0.00 1.20 103 0.03 3 1.16 6.47
BISHOP 0.00 1.31 135 0.16 16 0.97 5.18
SALINAS 0.00 3.87 160 0.75 31 2.42 12.83
PASO ROBLES 0.00 2.84 139 0.25 12 2.04 12.78
SANTA MARIA 0.00 1.95 82 0.09 4 2.38 13.95
Next report: Monday morning/December 10